R.Selvarani1*, B. Balamurugan 2*
1PhD Graduate Student, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. 2Assistant Professor, Department of Veterinary Gynecology & Obstetrics, Faculty of veterinary & Animal Sciences, Rajiv Gandhi South Campus, BHU, Mirzapur, Uttar Pradesh, India.
*Authors contributed equally to this paper
Introduction:
Forensic is a detailed investigation and collection of evidence irrespective of whether or not there is a specific legal case or enquiry pending (Cooper 1998). Forensic medicine (legal medicine) refers to the application of medical and veterinary knowledge to elucidation of evidence for courts. Forensic medicine and forensic pathology are reported as separate but closely related to one another. Specifically, forensic veterinary pathology focuses on multi species involving companion animals, farming livestock, and wildlife.
“Old Dog Learns a Trick” (Salvagni et al. 2012)-The quote is basically tells if you adopt an adult or senior dog, you may be amazed at their ability. Veterinary Pathology is central to many cases and protocols for forensic necropsy are becoming better established in veterinary pathology department. But the complexity of multispecies of forensic pathology leads to confusion in all aspects. So, I would like to describe some challenges in forensic pathology here!
Time of death:
First and foremost task is estimation of time since death. Estimation of post-mortem interval can direct pathologist in narrowing window of opportunity and eliminating specific events and suspects. For example, (1) In companion animals, investigators of suspected deliberate injury happened in the location at the estimated time of the incident (2) Wildlife crime investigations focused on shooting of animals and poaching at daylight time period (3) In farm livestock, establishing the questions of time of death through many factors such as death during transport, interruption of husbandry problems, suspected with insurance claims, failure to disposing of death carcasses.
Time of death can be detected rigor mortis and occurrence of known events at particular time. Body of knowledge and experience on rigor mortis which allows veterinary pathologists to overcome the challenges of determining time of death. Example: Soil type, hydrated time, quicklime on process of decay of pig cadavers. But there will be a chance of underestimating time of death. To overcome challenges, entomologist can support the identification of the types,stages of maggots, beetles, and collection of entomological evidence to determine time of death.
There are other scientific tools are available in the field such as histopathology, electron microscopic changes, post-mortem chemistry, post-mortem radiology. Forensic veterinary pathologist may utilize for the benefits of evidence in determining time of death.
Estimation of wound:
“Cats are not small dogs” – This proverb is opposite of forensic work. Normally, wound healing occurs more slowly in cats than dogs but granulation tissue formation appears at same time in both species. Similarly, “ponies are not small horses” because early inflammatory response of wound healing is more intense in ponies than horses. In addition, cutaneous wound healing differ in horses and cattle as horses showing rapid development of granulation of tissue, whereas differentiation of connective tissue in cattle 10 days after injury. Based on this, forensic veterinary pathologist must consider minute wound details in forensic cases. There may be confusion of lesions if improper wound identification in necropsy. Those inaccurate identification may leads to false evidence in court forensic cases.
To overcome challenges in estimation of wound, forensic veterinary pathologist can involve other experts such as radiologist. For example, projectile wounds in animals can be investigated by the radiologist. However, forensic firearms expert is useful to facilitate assessment of the parameters related with wound.
Drowning:
While finding estimation of drowning, pathologist need to correlate pathophysiology of drowning. For example, lung weight of normal healthy dogs mean±SD:19±5 g/kg body weight. In comparison, Giammona et al. (1967) reported that lung weight of drowned dogs mean±SD:34.9±5.3 g/kg bodyweight. To overcome challenges in drowning cases, forensic veterinary pathologist must be aware about the ratio of normal lung weight/body weight will vary as per breed, age, body condition.
Diseases state:
During necropsy, forensic veterinary pathologist need to look for findings of any disease lesions in died animals. Internal and external examination of necropsy animals would provide the opportunity to describe and record all lesions or injuries related with any disease and to allow interpretation of any tissue changes. For example, internal organs examination of any animals through post-mortem photography or radiography can be a valuable supplement in diagnosing and documenting any disease lesions in animals. Legally, this documentation may generate strong evidence in the court and scientifically, anyone can understand an important pathology and pathogenesis of lesions about any diseases.
Conclusion:
Veterinary forensics must have scholarly publication on interpretation of lesions, species-specific reference material and database, which strengthened the evidence in forensic veterinary pathology practices. Even though publications on forensic veterinary cases, some of the challenges are common in every cases. Forensic veterinary pathologist may consider those challenges at the time of investigations. Particularly, (1) extrapolation of details from one species to another species (2) lack of details of the timing of changes (3) limitations of experimental models to provide actual changes seen in every cases (4) requiring forensic pathologist to provide factual interpretation of post-mortem findings (Munro et al. 2013).
However, many other factors need to be discovered for the development and resolution of lesions in all species. Finally, educating undergraduate veterinary students, veterinary pathologists and practicing veterinarians in the scientific method which applies in forensic science to make sure that veterinary forensic science withstands the scientific and legal scrutiny applied to its medical counterparts. Therefore, we can extend the knowledge on necropsy through interdisciplinary collaborations in forensic veterinary pathology field.
References:
Cooper JE What is forensic veterinary medicine? its relevance to the modern exotic animal practice. In: Seminars in Avian and Exotic Pet Medicine, 1998. vol 4. Elsevier, pp 161-165.
Giammona ST, Modell JH (1967) Drowning by total immersion: effects on pulmonary surfactant of distilled water, isotonic saline, and sea water Am J Dis Child 114:612-616.
Munro R, Munro HMC (2013) Some Challenges in Forensic Veterinary Pathology: A Review J Comp Pathol 149:57-73.
Salvagni F, de Siqueira A, Barbosa A, Rodrigues C, Ramos A, Maiorka P (2012) Salvagni et al.; Forensic Veterinary Pathology: Old Dog Learns a Trick Editor’s Viewpoint Forensic Veterinary Pathology: Old Dog Learns a Trick Brazilian Journal of Veterinary Pathology 5:37-38.
